cover photo belongs to Gary A. Vasquez, USA TODAY Sports
Recently American Soccer Analysis published an article, Going to WAR for Points Above Replacement. It’s a fantastic read and an idea that I’m sure will stem new ideas for how statistics are utilized in soccer. Unfortunately they’ve beat me to the punch a little as I’ve been working on a new goalkeeping stat for the past few years, trying to find something more intuitive than the dreadful save percentage or goals against average. There are a number of issues with traditional goalkeeping statistics, the most notable being that they are only a sliver of a goalkeeper’s impact on the game. Goals Saved Above Replacement (GSAR) quantifies all areas of a goalkeeper’s actions, from shot stopping to cross handling to pass accuracy.
Identifying a baseline or replacement-level for MLS goalkeepers is tricky with salaries and talent levels constantly swelling over the past twenty years. Matching a “0 GSAR” goalkeeper with the median salary of MLS goalkeepers in 2018 ($132,625.00) proved to be the easiest route. Using this standard, we’ll take a look at seven different categories to obtain an overall GSAR rating, as well as put a dollar amount on each MLS goalkeeper’s performance from 2018.
Goals Saved Above Replacement
Each MLS goalkeeper has had their season broken down into seven categories.
shots <10 - The first two columns are shots from inside and outside ten yards. The distance measured is from the shooter to the goalkeeper, not the shooter to the goal.
While traditional expected goal models focus on a shooter’s location on the field, GSAR focuses on different criteria: where the shot passes the goalkeeper and how long the goalkeeper had to react.
A shot’s difficulty is not deemed by where it enters the goalmouth but how far the ball was from the goalkeeper when it intersected the goalkeeper’s dive line. This angle is affected by a goalkeeper’s starting position as well as where the shooter is located on the field. If a shot is taken near the end line, the ball will pass the goalkeeper within a few feet even if it is hit the upper corner. Similarly, if a goalkeeper is closer to the shooter, they “cut down the angle” and cover more of the goalmouth, putting the ball’s path closer to their body.
shots >10 - While the first category is largely impacted by a goalkeeper’s reaction abilities, the second has more emphasis on a goalkeeper’s ability to move his feet and general angle play.
pks - Penalties aren’t a large part of the MLS season, but they do occur once every six or seven games. On average a penalty has a success rate of around 80%.
crossing - This category takes into account if a goalkeeper punched, claimed, or (for a negative value) let a cross drop in a position they should have challenged for. The position has recently seen a swing towards favoring passive goalkeeping when it comes to crosses, which explains the relatively low ratings.
error - Covering a number of different areas, only negative numbers will be found here. This can include gifting a poor rebound to the opposition, giving away a penalty, or a number of other actions that result in creating another chance on goal.
misc - The miscellaneous tallies cover any non-tradition goalkeeping action. Slotted balls back to the center of the box are the most common, as well as any actions that don’t fit a proper formula, which are entered in by hand. Unique shot deflections and 1v1 situations (amongst other actions) can be found here. Hand-adjusted values make up less than .1% of all goalkeeping actions.
passing - Passing stats consider how often and where a goalkeeper completes a pass versus where a turnovers occur. A turnover at the other side of the field is negligible, while a turnover in front of one’s own goal returns a larger negative value.
Minutes and average GSAR/90 minutes are tacked on at the end.
Projected Salaries Based Off of GSAR
Placing a value on a goalkeeper’s season is challenging as one team’s willingness to spend high on goalkeeping doesn’t necessarily mean the rest of the league will. To find a fair expected payment, the salaries and GSARs were listed in descending order to find a trend between the two. This brings up certain issues but overall it puts every goalkeeper on an even playing field when it comes to receiving payment for their services.
As some goalkeepers didn’t play the whole season - whether due to injury or a coach’s decision - finding a projected dollar amount would either have to extrapolate a goalkeeper’s stats for a full 38 game season or shrink down the corresponding payment. For example, Attinella only played two-thirds of the season but compiled a 4.74 GSAR. Should his projected GSAR-based salary be off what he could have done over 38 games or should it account for only the games he played? With a goalkeeper’s true impact being dependent on what they can bring to the field every game, I opted to extrapolate the dollar amount out to 38 games.
Categories are explained in more detail below. Goalkeepers are sorted by the difference ($$.diff) in their projected payment minus their actual. “$$.diff” is not what goalkeepers deserved to be paid, simply just the difference between actual and deserved.
m.GSAR/gm - Simply dividing a goalkeeper’s GSAR over the minutes they played, unless the goalkeeper played less than 900 minutes in the season. If this was the case, a goalkeeper was given either a positive or negative .03, depending on their GSAR. It’s not a great siphoning method, but +/- .03 keeps backup goalkeepers’ GSARs from getting out of hand with such a small sample size.
adj.GSAR - What a goalkeeper’s GSAR would have been had they played all 38 games (3060 minutes, excluding stoppage time).
gsar.$$ - How much a goalkeeper deserves to be paid, converted from a goalkeepers’ adj.GSAR. The conversation formula is based off the previous orange and white graph.
$$.diff - Goalkeepers are sorted by this column, which simply subtracts real.$$ from gsar.$$. Tyler Miller was underpaid by $333,503 while Andre Blake was overpaid by $410,805.
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